This invention relates, generally, to the storage, handling and use of removable electronic circuit cards, and, more specifically, to the storage, handling and use of the related MultiMediaCard (xe2x80x9cMMCxe2x80x9d) and Secure Digital (xe2x80x9cSDxe2x80x9d) non-volatile memory cards.
The physical and electrical specifications for the MMC are given in xe2x80x9cThe MultiMediaCard System Specificationxe2x80x9d that is updated and published from time-to-time by the MultiMediaCard Association (xe2x80x9cMMCAxe2x80x9d) of Cupertino, California. Versions 2.11 and 2.2 of that Specification, dated June 1999 and January 2000, respectively, are expressly incorporated herein by this reference. MMC products having varying storage capacity up to 64 megabytes in a single card are currently available from SanDisk Corporation of Sunnyvale, California, assignee of the present application, and a capacity of 128 megabytes is expected before long. The MMC products are described in a xe2x80x9cMultiMediaCard Product Manual,xe2x80x9d Revision 2, dated April 2000, published by SanDisk corporation, which Manual is also expressly incorporated herein by this reference. The MMC card has a rectangular shape, with dimensions of 24 by 32 mm., and a 1.4 mm. thickness. Seven electrical contacts are provided on the outside of the card in a row along one end.
The newer SD Card is similar to the MMC card, having the same size except for an increased thickness that accommodates an additional memory chip. It""s thickness is 2.1 mm., with narrow side rails along its length having a 1.4 mm. thickness. A primary difference between the two cards is that the SD Card includes three additional electrical contacts in the row along one edge. The other contacts of the SD Card are the same as those of the MMC card in order that sockets designed to accept the SD Card will also accept the MMC card. The electrical interface with the SD card is further made to be, for the most part, backward compatible with the MMC product described in version 2.11 of its specification referenced above, in order that few changes to the operation of a host system to which the card is connected need to be made in order to accommodate both types of cards.
The small size of these and other forms of commercial non-volatile memory cards has many advantages, including the ability to insert them into very small host devices, such as cellular telephones, MP-3 audio players of music that is stored on such cards and in various hand held personal electronic devices. Further, very little space is required for storage of the memory cards when not being used in such devices. But the small size of the cards subjects them to the possibility of being misplaced so that a specific card is not readily available when desired to be inserted into such a device.
Accordingly, a holder for one or more small integrated circuit cards is provided where the card(s) is easily inserted and removed by hand, the holder is easy to handle when the card(s) is inserted, and the holder may conveniently be carried on the person such as by attachment to a key ring or chain. In one form, the holder is made from molded plastic and contains one or more slots that are each adapted to have a card inserted entirely therein and retained by friction in a manner that allows it to be easily removed by hand. To facilitate removal, as an example, the holder exposes a portion of the card surface through a side opening that allows the user to touch and frictionally engage the card with a finger. The holder may be transparent to allow any label on the card to be read without having to remove the card from the holder. A notch may be included in one wall of the holder adjacent the card opening in order to expose a row of contacts on the card, thus allowing the card to be inserted into a receptacle of electronic equipment without having to first remove the card from the holder. Two or more card slots may also be included in the holder. In a specific embodiment, the cross-sectional shape of the slot is made to accommodate both of the MMC and SD non-volatile memory cards.
Additional features and advantages of the present invention will become apparent from the following description, which should be taken in conjunction with the accompanying drawings.